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CryptoHack

A free, fun platform for learning modern cryptography

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Learn By Doing

Learn about modern cryptography by solving a series of interactive puzzles and challenges. Get to know the ciphers and protocols that secure the digital world by breaking them.

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Level Up

Earn points by solving challenges. Finish categories to earn trophies and gain levels to track your progress. Can you reach the top of the scoreboard?

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Fresh Challenges

We are constantly creating new challenges to keep your crypto knowledge up to date. Expect exciting brainteasers and whole new categories as the site continues to grow.

New Challenges
Do you have good eyes? (Breizh CTF) CTF Archive 0
RSATogether (ECSC 2024 (Italy)) CTF Archive 0
Authentification 1 (Breizh CTF) CTF Archive 0
One Round Crypto (ECSC 2024 (Italy)) CTF Archive 0
Greatest Common Multiple (CODEGATE CTF) CTF Archive 0
Weekly Top Users
#1 FrancoErmasi 2565
#2 s4hm4d 2180
#3 coconut 2025
#4 berndoJ 1945
#5 IIJ_01_Aatif 1845
Recent Solves
Bytes and Big Integers yazuac
Resisting Bruteforce User_Name_735171
Base64 yazuac
Greatest Common Divisor frostbean
Keyed Permutations User_Name_735171
Recent Solutions
Confusion through Substitution numberFreak 0
Extended GCD numberFreak 0
Greatest Common Divisor numberFreak 0
Round Keys numberFreak 0
Favourite byte numberFreak 0

Level Up

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